[Axiom-developer] [#180 bug #9216 differentiating sums with respect to a bound is wrong]

[kratt6]

Changes 
http://page.axiom-developer.org/zope/mathaction/180Bug9216DifferentiatingSumsWithRespectToABoundIsWrong/diff
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??changed:
-From BillPage Wed Jun 22 13:57:40 -0500 2005
-From: Bill Page
-Date: Wed, 22 Jun 2005 13:57:40 -0500
-Subject: (new) bug #9216 differentiating sums with respect to a bound is wrong
-Message-ID: <address@hidden>
differentiating sums with respect to a bound is wrong

  The function $n\mapsto\sum_{k=1}^n f(k,n)$ is well defined only for integral 
values of $n$ greater than or equal to zero. There is not even consensus how to 
define this function for $n<0$. Thus, it is not differentiable. The fix I 
propose is thus

<a href="dvdpatch2.patch">dvdpatch2.patch</a>


??changed:
-+    ddiff l ==
-+      prefix(sub(D::O, third(l)::O), [eval(first(l), second(l), third(l))::O])
-+
-and
-+    setProperty(opdiff, SPECIALDISP, ddiff@(List F -> O) pretend None)
  +    ddiff l ==
  +      prefix(sub(D::O, third(l)::O), [eval(first(l), second(l), 
third(l))::O])
  +

and::

  +    setProperty(opdiff, SPECIALDISP, ddiff@(List F -> O) pretend None)

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forwarded from http://page.axiom-developer.org/zope/mathaction/address@hidden